Simple instantaneous power modulation scheme for single-phase high-frequency link microinverter for low-power PV applications

Abstract

This paper presents a single-phase HF-Iink microin verter for low-power PV applications with a simple instantaneous power modulation scheme; the topology is based on the DCIDC Dual-Active-Bridge (DAB) converter without the intermediate DC-link, which reduces the number of power processing stages. The modulation scheme is simple, and it can be implemented with low-computational effort in low-complexity devices, leading to lower cost of the system. Simulation results are presented for a grid-connected open-loop system and its feasibility validated through an experimental platform for the proposed modulation strategy. Experimental results validate the proof-of-concept of the proposed modulation scheme for the presented microinverter system.978-1-4799-6735-3/15/$31.00 ©2015 IEEE

A single-phase DC-AC dual-active-bridge based resonant converter for grid-connected photovoltaic applications

“…This converter offers soft switching operation, albiet not over its entire output power range [11]. To extend the power range over which soft switching exists and to grant dc-ac conversion functionalitiy to the DAB converter topology, different methods have been proposed in the literature [4][5][6][7][8][9][10][23][24][25][26][27][28][29]. Figure 1.12 shows the circuit diagram of the series resonant dc-dc isolated DAB converter.…”

“…The DAB based dc-ac converter topology presented in [27], discuses the substitution of the output bridge by a half-wave cycloconverter that integrates the converter with the acgrid. This paper proposed a Single Phase-Shift (SPS) modulation between the input and output bridges with one control angle φ that regulates the power transfer.…”

“…The half-wave cycloconverter discused in [27] was proposed earlier in [7,[24][25][26]. In [7,[24][25][26], the modulation used to operate the converter is the same DPS modulation as proposed in [23], mentioned in Section 1.3.1 and further described in Section 1.5.3.…”

“…In [7,[24][25][26], the modulation used to operate the converter is the same DPS modulation as proposed in [23], mentioned in Section 1.3.1 and further described in Section 1.5.3. Such modulation has the benefit of an increased soft-switching operating region in comparison to the SPS modulation used in [27]. Similarly to [6], a series connected resonant tank is added to further increase the overall converter efficiency.…”